Conventional orthopedic braces embody a wide range of structures and serve the similar purpose of supporting and stabilizing a joint when worn on the body of a user. When used in this manner, such braces may help an existing injury heal, or prevent future injuries from occurring. A brace can add support and stability to a healthy skeletal joint to reduce the risk of injury when the joint is subjected to undue stress. Alternatively, braces may help provide relief and restore functionality to an injured person by providing stabilizing support to a weakened skeletal joint to reinforce it and reduce the risk of sustaining further injury. An orthopedic brace must be sufficiently secured to a user so it can provide the necessary support and stability as needed.
Patients commonly wear orthopedic knee braces after surgery for treatment of an injury to the knee joint. Knee braces may serve many purposes. For instance, they stabilize the knee joint and control its lateral movement, or knee braces help limit joint flexion and/or extension in an adjustable and controllable manner to prevent recurrence of injury to the knee.
Certain types of knee injuries require special attention. An injury of the posterior cruciate ligament (PCL) would benefit from a PCL knee brace designed to provide support to the back of the upper calf throughout the range of motion to prevent unwanted shifting. In a recently injured or post-operative patient, this may also lessen the lengthening of the PCL during healing. For a patient with a PCL having healed in a lengthened state, the brace may prevent such undesirable shifting to give the patient the feeling of added stability. The tension in the PCL changes dynamically relative to the knee flexion angle. Therefore, the PCL brace may theoretically apply a correspondingly dynamic load to offset the tension in the posterior cruciate ligament.
Conventional PCL braces offer a strap that provides static ACL (anterior cruciate ligament) or PCL support, and such strap is often incorporated into a brace providing multiple ligaments stabilization. No known solutions have been provided which offer a dynamic load specifically on the PCL, and an objective of the disclosure is to provide a dynamic tensioning system for an orthopedic device.
One type of an ACL brace is found in U.S. Pat. No. 7,811,242 and features a hinge arranged to dampen a knee as it goes into extension. A posterior force is applied to the tibia, preventing anterior movement, which stresses the ACL, and reducing the anterior translation. The hinge is arranged to increase knee flexion angles to dampen knee extension and reduce shear forces at the knee.
Another example found in U.S. Pat. Nos. 5,954,677 and 7,309,322 describes a PCL brace arranged to specifically rehabilitate a knee by providing an anteriorly directed tibial force by spring tension to a patient's leg and weight. The load exerted on the knee is constant or static over the entire range of motion.
There are various ways to secure and tighten an orthopedic brace to the body of a user. Many knee braces use straps that attach to a brace frame via clips or tabs, such as D-rings. These straps often secure the brace to a user's leg above and below the knee. Adjustable straps, such as those employing a hook and loop technique utilizing Velcro®, must be manually tightened so that when tension applies to each strap, the brace is urged closer against the user's body. Shortening or lengthening the straps causes the fit of the brace to be tightened or loosened, respectively.
Manually adjusting straps on a brace in this manner is cumbersome and can be quite time consuming, especially when there are multiple straps on a single brace and the user must constantly readjust the tension in each strap. Manually adjusting each strap is an inaccurate way to gauge the general fit of the brace on a user. It is difficult to determine how much a knee brace should be tightened by separate straps that secure the top and bottom portions of the brace to a user's leg above and below the knee, respectively. This is because each strap must be tightened individually and may require a different amount of tension.
Another way of securing an orthopedic brace to the body of a user is by threading a lace in a zigzag pattern through slots on opposite parallel sides of the brace. Pulling each end of the lace creates tension that urges the threaded brace against a user. This lacing system has many drawbacks. For instance, it is difficult to ensure an even distribution of tension along the entire length of the lace due to the slack created around each slot. Higher tensioned portions of the lace, such as those near the ends, cause the brace to be tighter in certain areas. This uneven tensioning can adversely affect the function of the brace, and make it uncomfortable to wear. It is difficult to untighten or redistribute tension in these lacing systems since the user must loosen both ends of the lace, which are often knotted to maintain the initial tension.
Conventional dial tensioning systems also exist for regulating the tension applied to an attached cable. Such systems often incorporate an internal helically wound band spring interposed between the dial and an inner housing. There are also drawbacks to these types of tensioning systems, including the ease by which they can be overtightened. This makes gauging how much a cable or wire has already been tensioned very inaccurate. Traditionally, a user adjusts the cable until he or she feels that it is sufficiently tight. This requires a fair bit of guesswork on behalf of the user.
One of the objectives of the present disclosure is to provide a tightening system with a dynamic tension system that automatically distributes equal lateral tightening forces to a cable, and also makes it easy to determine tension in the cable while it is being tightened.
Adjusting the tension used to secure a brace to a user affects its function, fit and comfort. The ability to increase the tension applied is important because insufficient tension can prevent the brace from staying in place on the limb, and diminish its ability to stabilize or protect the limb. Overtightening the brace by applying too much tension, however, can restrict the individual's blood flow and make the brace very uncomfortable to wear. Therefore, it is another object of the present disclosure to provide a tightening system with an adjustment mechanism that prevents or reduces such overtightening.
It may be desirable to apply loads to various portions of a wearer's anatomy according to desired treatment of the wearer's anatomy. Because of injury risk, there is exists a need to carefully regulate the degree of the load to prevent the wearer from applying an excessive load.
Many orthopedic braces have tightening means that make the brace bulky, difficult to don and properly tighten, difficult to configure, and uncomfortable to wear. There exists a substantial need for a tightening system with an adjustment mechanism that can be quickly and easily adjusted during use, including during either extension or flexion of the brace. It is preferable that a user can adjust the adjustment mechanism by using just one hand, and that the user knows when an initial desired loading has been achieved. Finally, it is desirable that the tightening system can be easily loosened and incrementally adjusted without losing tension in the cable due to continued use. There also exists a need in certain applications of applying a load against the anatomy and regulating the degree of the load. The present disclosure addresses all of these aforementioned needs and other needs addressed or flowing from the below discussion.